Vertical axis wind turbine

ABSTRACT

The present disclosure relates to a turbine including a central axis, a variable pitch blade, and a frame link operably coupled with the central axis and the blade, the blade configured such that as the blade rotates about the central axis, the blade may be pivoted relative the frame link from a first position to a second position. The present disclosure also relates to a method for reducing the negative torque on a wind turbine including providing a turbine having variable pitch blade for rotation about a central axis, the blade operably coupled with the central axis via a frame link, and positioning the blade, frame link, and central axis, such that the blade is pivoted relative the frame link from a first position to a second position so as to reduce negative torque on the central axis caused by the blade heading generally into oncoming wind.

This application claims priority to U.S. Application No. 61/334,431, filed May 13, 2010, the content of which is hereby incorporated in its entirety by reference.

FIELD OF THE INVENTION

The present disclosure relates to systems and methods involving improved vertical axis wind turbines. More particularly, the present disclosure relates to variable pitch, aerodynamic vertical axis wind turbines.

BACKGROUND OF THE INVENTION

Wind energy is a clean, ideal solution to the world's energy needs. As such, a variety of energy-producing wind turbines have been designed and used. One example of a wind turbine is the vertical axis wind turbine. However, the design of traditional vertical axis wind turbines generally have at least two distinct flaws. First, vertical axis wind turbines are affected by negative torque or backlash. That is, after a blade catches the wind and is forced around the vertical axis of the turbine, the blade goes around the back side away from the oncoming wind, and then comes back into the wind. When in this position, the force of the wind wants to force the blade backwards in the wrong direction, creating negative torque or backlash. Ultimately, this backlash can greatly reduce the efficiency of vertical axis wind turbines. Most traditional vertical axis wind turbines operate in the range of about 38% efficiency. Secondly, most traditional vertical axis wind turbines are not self-starters. That is, when the wind begins to blow, a generator or motor is generally needed in order to begin the process of rotation of the wind turbine blades.

Thus, there exists a need in the art for an improved vertical axis wind turbine. Particularly, there is a need in the art for a variable pitch, aerodynamic vertical axis wind turbine, which may reduce the amount of effect that negative torque or backlash has on the wind turbine. Additionally, there exists a need in the art for variable pitch, aerodynamic vertical axis wind turbines that can self-start.

BRIEF SUMMARY OF THE INVENTION

The present disclosure relates to systems and methods for pivoting the wind blade(s) of a vertical axis turbine to reduce or minimize blade torque loss. This can change the overall efficiency and the ability to create greater torque with larger blades. Furthermore, this unique type of pivot blade can be designed to produce more power at less cost.

The present disclosure, in one embodiment, relates to a turbine including a central axis, a variable pitch blade, and a frame link. The frame link is operably coupled with the central axis and the variable pitch blade. The variable pitch blade is configured such that as the blade rotates about the central axis, the blade may be pivoted relative the frame link from a first position to a second position.

The present disclosure, in another embodiment, relates to a method for reducing the negative torque on a wind turbine. The method includes providing a turbine having variable pitch blade for rotation about a central axis, the variable pitch blade operably coupled with the central axis via a frame link, and positioning the variable pitch blade, frame link, and central axis, such that the variable pitch blade is pivoted relative the frame link from a first position to a second position so as to reduce negative torque on the central axis caused by the blade heading generally into oncoming wind.

The present disclosure, in yet another embodiment, relates to a wind turbine comprising a variable pitch blade. In addition to rotating about a central axis of the wind turbine, the blade is configured to transition from a first position to a second position about a pivot point of the blade.

While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosure. As will be realized, the various embodiments of the present disclosure are capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter that is regarded as forming the various embodiments of the present disclosure, it is believed that the embodiments will be better understood from the following description taken in conjunction with the accompanying Figures, in which:

FIG. 1 is a perspective view of a wind turbine according to one embodiment of the present disclosure.

FIG. 2A is a top view of the wind turbine according FIG. 1.

FIG. 2B is a top view of the wind turbine according FIG. 1.

FIG. 3 is a top down schematic view of a wind turbine in operation according to one embodiment of the present disclosure.

FIG. 4 is a top down schematic view of the drag and torque experienced by a wind turbine according to one embodiment of the present disclosure.

FIG. 5 is a wind model of wind turbine blade positions according to one embodiment of the present disclosure.

FIG. 6A is a perspective view of a wind turbine according to another embodiment of the present disclosure.

FIG. 6B is a close-up view of a wind turbine blade according to the embodiment of FIG. 6A.

FIG. 7 is a perspective view of a wind turbine according to yet another embodiment of the present disclosure.

DETAILED DESCRIPTION

The present disclosure relates to novel and advantageous systems and methods for vertical axis wind turbines. Particularly, the present disclosure relates to novel and advantageous variable pitch, aerodynamic vertical axis wind turbines. Additionally, the present disclosure relates to novel and advantageous variable pitch, aerodynamic vertical axis wind turbines that can self-start. One economic sector for such vertical axis wind turbines includes small to large-scale power generation.

A vertical axis wind turbine according to embodiments of the present disclosure may be driven by wind coming towards the turbine from any direction. Generally, upon being contacted by wind flow, blades of the turbine may rotate the turbine about a vertical axis thereof. The rotation of the wind turbine may then be transferred to a power generator via an output shaft or link for power generation.

FIG. 1 illustrates one embodiment of a vertical axis wind turbine according to the present disclosure. As shown in FIG. 1, a vertical axis wind turbine 100 of the present disclosure may include a central axis 102, about which the wind turbine may rotate, and one or more variable pitch blades 104, generally positioned about, and operably coupled with, the central axis 102. While FIG. 1 illustrates three blades 104, it is recognized that any other suitable number of blades may be used. Although not required, the variable pitch blades 104 may be configured substantially equidistant from each other and/or configured substantially equidistant from the central axis 102.

In one embodiment, the central axis 102 may be coupled to one or more output links for operable coupling to an output means, such as a generator or drive train, to produce or otherwise harness and use the output energy of the vertical axis wind turbine 100. The central axis 102 may be coupled with the output means via output link means, which include any suitable means for coupling the central axis 102 with the output means, e.g., generator or drive train. As an example only, in some embodiments, the central axis 102 may be coupled with the various embodiments of magnetic drive systems described in U.S. Pat. No. 7,385,325, titled “Magnetic Propulsion Motor,” issued Jun. 10, 2008, U.S. Pat. No. 7,777,377, titled “Magnetic Propulsion Motor,” filed Jun. 9, 2008, and U.S. application Ser. No. 12/548,233, titled “Magnetic Propulsion Motor,” filed Aug. 26, 2009, each of which is hereby incorporated by reference herein in its entirety. These drive systems may increase or enhance the output power and/or torque of wind turbine 100. However, translating the mechanical power from the vertical axis wind turbine 100, with or without additional drive systems, to generators can produce clean power, such as but not limited to 60 Hz AC power, which can then be transmitted to a power grid or used locally.

As discussed in the above-incorporated patents and application, a magnetic drive system in some embodiments, may include one or more drive magnets, a motion magnet, and an acceleration field. The drive magnet may include magnetic shielding, typically on a portion thereof, altering the magnetic field of the drive magnet. In some embodiments, the motion magnet may have a cross-section that is generally in the shape of a ‘V’ or ‘A’. The acceleration field may be created by the interaction between the drive magnet and the motion magnet as the motion magnet is passed through the altered magnetic field of the drive magnet. The altered magnetic field of the drive magnet may often be near the first end of the drive magnet. The motion magnet may be operably coupled to an output shaft and rotate around the central axis of the output shaft. Multiple drive magnets may also be added, thereby adding more acceleration fields created by the interaction between the drive magnets and motion magnets.

Each blade 104 may coupled to the central axis 102 by one or more frame links 106. Frame links 106 may take on any suitable shape or configuration, and are not limited by the frame links 106 illustrated in FIG. 1. For example, while FIG. 1 illustrates two linear frame links per blade, it is recognized that more or less frame links 106 per blade may be used, that any other shape and/or configuration than linear may be used, and that a blade may be coupled with the central axis 102 using more or less frame links 106 than another blade, etc. Blades 104 may be made of any suitable material, including but not limited to, metals, including lightweight, durable metals and metal alloys, plastics, ceramics, rubbers, etc. or any suitable combinations thereof. In some embodiments, blades 104 may generally have an aerofoil cross-sectional shape; however, in other embodiments, any other shape blade may be suitable, including but not limited to linear blades, spiraled or twisted blades, or other blade shape that can enable blades 104 to capture or harness wind power. One purpose of a more aerodynamic blade is to allow the vertical axis turbine 100 to operate with reduced or minimal negative torque and increased or maximized positive torque, as will be discussed in further detail below. In some embodiments, it may be desirable to accomplish this with the least amount of mechanical movement in order to increase reliability.

As better illustrated in FIGS. 2A and 2B, blades 104 may be coupled with frame links 106 at one or more pivot points 108, such that the blades may rotate between at least two positions about pivot points 108. As will be described in more detail with respect to the schematic of FIG. 3, the variable pitch blades 104 of the present disclosure may each individually achieve, or pivot between, one or more blade positions as they rotate about central axis in order to increase positive torque and/or decrease negative torque on the vertical axis turbine 100. Blades 104 can be varied between such blade configurations by various mechanisms such as, inertial forces, mechanical means, electrical actuation, hydraulic or pneumatic means, fluidics or aerodynamics, or any other suitable means or combination of means. Pivot points 108 may couple a blade 104 with a frame link 106 at generally any suitable point along the blade, including but not limited to, at a tip or end of the blade, or at any position between the tips or ends of the blade, as illustrated in FIGS. 1, 2A, and 2B. The pivot point may be selected based on the desired configuration of the vertical axis turbine 100 and/or the desired use therefor.

FIG. 3 is a top down schematic view of a vertical axis turbine 100 according to one embodiment of the present disclosure. In the schematic, wind forces are illustrated as moving from the right side of the diagram to the left side. Blade position 302, as illustrated in FIG. 3, illustrates a blade 104 in what is referred to herein as a “closed” position where the blade can harness the oncoming wind. In blade position 302, the wind approaching blade 104 encounters an increased amount of the blade's surface area, therefore increasing or maximizing the wind force experienced by the blade. As will be recognized, the wind force may be used to position and maintain the blade 104 in a closed position at blade position 302. In the closed position, blade 104 may be forced against a closed position limiter, such as a closed position stop 304, described in more detail below, which can keep the blade 104 from over-rotating out of the closed position. The closed, or substantially closed, position, at and/or around blade position 302, can allow positive torque to be applied to the blade 104 and transferred, such as by frame links 106, to the central axis 102 thereby converting the wind force to rotational motion of the vertical axis turbine 100. As blade 104 harnesses the wind force in blade position 302, blade 104 may rotate about central axis 102 (in a counter-clockwise direction, as illustrated in FIG. 3) toward another blade position 306, as blade 104 rotates into the oncoming wind.

Blade position 306 illustrates a blade 104 moving generally against the direction of the oncoming wind wherein blade 104 is in what is referred to herein as an “open” position where the blade can decrease the amount of negative torque it transfers to the central axis 102. The blade's 104 transition from a closed position to an open position can begin as the blade leaves blade position 302 or may begin at any point during the rotation about central axis 102 between blade position 302 and blade position 306. In some embodiments, the transition may begin when blade 104 begins to be forced away from the closed position limiter 304, which in some embodiments, may be caused by the force of the wind and/or the inertial forces caused by rotation of the blade about central axis 102. As blade 104 approaches position 306, the wind force may cause the blade 104 to move toward and abut against an open position limiter, such as an open position stop 308, described in more detail below, which can keep the blade 104 from over-rotating out of the open position. Because at and/or around position 306, blade 104 is generally moving in a counter-productive direction into the wind, the vertical axis turbine 100 may experience a negative torque. Accordingly, it can be desirable to minimally expose the blade to the drag force that may result from encountering the oncoming wind at this position. In embodiments of the present disclosure, when blade 104 is in an open, or substantially open, position, at and/or around blade position 306, a reduced or minimum amount of surface area of blade 104 may be exposed to the oncoming wind, thus reducing or minimizing the negative torque or backlash that would otherwise result if the blade 104 was left in a closed position.

Intermediate blade position 310 illustrates an example intermediate position of blade 104 as the blade moves from an open position to a closed position. While generally illustrated as about half way between an open and closed position, an intermediate position may include anywhere between the open and closed positions. As stated above, with respect to the move from a closed position to an open position, in some embodiments, the transition may begin when blade 104 begins to be forced away from the open position limiter 308, which in some embodiments, may be caused by the force of the wind and/or the inertial forces caused by rotation of the blade about central axis 102. As the blade 104 transitions from an open position to a closed position, it may begin to expose an increased surface area of blade to the oncoming wind, and thereby begin to transfer positive torque to the central axis 102. However, in some embodiments, the blade may not experience as much positive torque as if it were in a full closed position, as shown with respect to blade position 302. As turbine 100 continues to rotate in, for example, the counter-clockwise direction as shown, blade 104 may be forced nearer to a closed position and therefore nearer to an accompanying closed position limiter 304. Generally, as the blade approaches blade position 302, the closer blade 104 is to a closed position, the more wind force experienced by the blade, and accordingly the more positive torque translated to the central axis 102 and wind turbine 100.

Open and closed position limiters 304 and 308 may be any suitable mechanism for keeping the blade 104 from over-rotating past the desired rotation, e.g., rotating past or out of the open or closed positions, at times when it is not desirable for the blade to be rotated out of those positions. In one embodiment, the open and closed limiters 304 may be spring stops. More particularly, in one embodiment, one or more spring stops may be used to position or stop the blade 104 in a closed position, and one or more spring stops may also be used to position or stop the blade 104 in an open position. However, position limiters may be provided by other means, including but not limited to, magnets, hinge means that provide for limited movement, rubber or plastic stops, etc. or any combination of means. In still other embodiments, position limiters are not required and may be eliminated. The position limiters 304 and 308 may be generally used to keep the blade 104 in a desired position relative to its position as it rotates about central axis 102 relative to the wind direction. In further embodiments, a variety of blade orientations are possible depending on the number and positioning of position limiters. While not limiting, as shown in FIG. 3, the open and closed position limiters may be positioned such that an approximate range of 90 degrees of blade pivot is allowed between the open and closed positions of the blade. However, it is recognized that any pivot range of greater or lesser angle (such as but not limited to angles from about 45 degrees to about 135 degrees and greater) may be used according to other embodiments of the present disclosure. For example only, pivot ranges of less than 90 degrees can use less mechanical pivot movement between open and closed positions, thereby reducing the amount of overall mechanical movement experienced by the blade 104.

In some embodiments, the position limiters 304 and 308 can assist in pushing the blade 104 away from its current position (e.g., a closed position) to the next position (e.g., an open position) when it is desired to do so. In addition, the pivot points 108 may be designed and/or configured to control the speed at which blade 104 transitions from one position to another.

FIG. 4 illustrates, in schematic form, aerodynamics of the blades 104 of a vertical axis wind turbine 100 according to an embodiment of the present disclosure. As shown in FIG. 4, in blade position 302, blade 104 may be pivoted to a closed position, such that when moving with the wind, the cross-sectional area and the drag coefficient are increased, thereby generating positive torque, which is then translated to the rotational movement of the overall turbine 100. In contrast, in blade position 306, blade 104 may be pivoted to an open position, such that when rotating into the oncoming wind, the cross-sectional area and the drag coefficient are decreased, thereby reducing the negative torque translated to the overall turbine 100. Also illustrated in FIG. 4, is blade 104 in transition from an open position to a closed position, wherein in the upwind position of FIG. 4, blade 104 may generate a lifting force in the direction of rotation in order to begin generating a positive torque. As discussed above, generally, as the blade approaches blade position 302, the closer blade 104 is to a closed position, the more wind force experienced by the blade, and accordingly the more positive torque translated to the central axis 102 and wind turbine 100.

FIG. 5 illustrates a wind model of the blade positions 302, 306, 310 described above, showing the fluids or aerodynamics of the blades 104 of a vertical axis wind turbine 100 according to one embodiment of the present disclosure. As with FIGS. 3 and 4 above, the direction of the wind flow in FIG. 5 is from right to left. As with the above figures, blade position 302 depicts a blade 104 in a closed position harnessing the oncoming wind, and thus transferring positive torque to the central axis 102 and the overall turbine 100. As indicated in the model of FIG. 5, the wind flow can be generally caught by the blade pocket, and forced to circumvent the width of blade 104. For some embodiments, position 302 may illustrate the highest, or one of the highest, positive torque points for the turbine 100. As with FIGS. 3 and 4 above, blade position 306 depicts a blade 104 in an open position. In such position, the wind flow meets the blade 104 with a reduced or minimal amount of resistance, as it encounters significantly less surface area of the blade 104 than in a closed position. Accordingly, the wind turbine 100 may experience a reduced or minimal amount of negative torque or backlash in blade position 306. Similar to FIGS. 3 and 4, intermediate position 310 depicts an example intermediate position of blade 104 as the blade moves from an open position to a closed position, wherein the blade generates an intermediate amount of positive lift and corresponding positive torque for the turbine 100.

FIG. 6A illustrates another embodiment of a vertical axis wind turbine 600 according to the present disclosure. As will be recognized, turbine 600 may include a central axis 602 and one or more blades 604 operably connected to central axis 602. One or more frame links 606 may be used to couple each of the blades 604 with the central axis 602. Central axis may be coupled with output link 608 for coupling with an output means, such as a generator or drive train, as described above. As illustrated in further detail in FIG. 6B, a pivot point 610 may be provided between the ends of blade 604. However, it is recognized that the pivot point 610 could be suitably provided at either end of the blade 604. Frame link 606 may also include a closed position limiter 612 and/or an open position limiter 614, which can keep the blade 604 from rotation away from the closed and open positions when it is desirable to keep them from doing so.

FIG. 7 illustrates yet another embodiment of a vertical axis wind turbine 700 according to the present disclosure. As will be recognized, turbine 700 may include a central axis 702 and one or more blades 704 operably connected to central axis 702. A frame link 706 may be used to couple each of the blades 704 with the central axis 702. Central axis may be coupled with an output link for coupling with an output means, such as a generator or drive train, as described above. Central axis 702 may have any suitable configuration, such as a cylindrical configuration, a flared configuration (as shown), or any other suitable configuration. Central axis 702 may further have any suitable thickness, including varying thickness, which in some embodiments, may depend on the desired strength of central axis 702 and/or the likely wind velocities to be encountered.

In some embodiments, a vertical axis wind turbine may include a vane assembly 708 and follower links 710. The vane assembly 708 may comprise a vane 712 and a link 714 where one end of the link may be coupled to the central axis 702 and the other end may be coupled to the follower links 710, which may be coupled to each of the individual blades 704. The link 714 can be fixed to the vane 712 such that as the wind direction changes, and the vane rotates about the central axis 702, the link follows and transfers motion to the follower links.

A pivot point 716 may be provided at an end of each blade 704. However, it is recognized that the pivot point 716 could be suitably provided at any position along blade 704. More particularly, as shown in FIG. 7, in one embodiment, blade 704 may include an end A and an end B, where end A can be generally fixed with, for example, a bearing, and the blade 704 may rotate about the bearing or axis at end A; end B may be fee to rotate about the axis at end A. End A may be supported by a variety of bearings or similar means, including the use of lubricant for motion facilitation. End B may further be coupled to a follower link 710 as described above. End B may be allowed to travel along a roller bearing or other suitable means, to permit free rotation about the axis at end A. This, for example, could reduce friction and improve ease of movement of blade 704.

In some embodiments, the electrical power produced by the generator coupled to the turbine may be locally consumed immediately upon its production. In other embodiments, it may be desirable to store the energy for later use. The energy produced by vertical axis wind turbines of the present disclosure may further be stored as described in U.S. application Ser. No. 13/106,377, titled “System and Method for Storing Wind Energy and/or Generating Efficient Energy,” filed May 12, 2011, which is hereby incorporated by reference herein in its entirety. Generally, when there is a need to store the energy produced, for example, by the wind turbines, the energy may be used to drive an electrolysis process to decompose water to produce hydrogen gas (H₂) and oxygen gas (O₂). The separated hydrogen and oxygen gas may then be autoxidized to produce hydrogen peroxide (H₂O₂). The H₂O₂ may be easily stored, such as during times of low energy demand. When more energy is needed, the H₂O₂ may be decomposed to produce heat, steam, and oxygen. The steam may be used to run a steam engine to create mechanical power, which in turn may be used to run a generator. The generator can create AC power, which may be output to a power grid or used locally. The steam and oxygen that is produced may then be reclaimed for re-use in the electrolysis process. The cycle may then be repeated. In this regard, energy generated by a vertical axis wind turbine may be stored for use at a later time.

The various embodiments of vertical axis wind turbines of the present disclosure provide various advantages over traditional wind turbines. Embodiments of the present disclosure can reduce or minimize the amount of negative torque on the wind turbine by pivoting, feathering, etc. the blades out of the wind, and can also use lift and drag to generate more overall positive torque than traditional vertical axis turbines. Accordingly, the improved vertical axis wind turbines of the present disclosure can increase or maximize output efficiency of the turbine to a generator. In doing so, the power generation capacity of a given turbine size can be significantly increased as compared to traditional vertical axis wind turbines. Furthermore, the present design permits self-starting of the wind turbine, therefore obviating the need for additional starting elements that need to be utilized whenever the wind begins to blow. The lift provided by the blades and reduced negative torque can help enable self-starting power generation. Additionally, the wind turbines of the present disclosure can have the benefit of low decibel emission, thereby reducing overall noise pollution during use. This provides the added benefit of minimizing harm to surrounding wildlife. Noisier wind turbines often cause birds and bats to become disoriented and become injured or die.

Although the various embodiments of the present disclosure have been described with reference to preferred embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the present disclosure. For example, although discussed with respect to a vertical axis wind turbine, the term “vertical” is not meant to be limiting, and it is recognized that the various embodiments of wind turbines of the present disclosure may be oriented with the central axis at any suitable angle, including horizontal, or any other non-vertical or non-horizontal angles. 

1. A turbine, comprising: a central axis; a variable pitch blade; and a frame link operably coupled with the central axis and the variable pitch blade, the variable pitch blade configured such that as the blade rotates about the central axis, the blade may be pivoted relative the frame link from a first position to a second position.
 2. The turbine of claim 1, further comprising a plurality of variable pitch blades, operably coupled with the central axis via a respective frame link, the variable pitch blades each configured such that it may be pivoted relative to its respective frame link, from a first position to a second position.
 3. The turbine of claim 2, wherein the blades have an aerofoil shape.
 4. The turbine of claim 2, further comprising an output link operably coupled with the central axis and a magnetic drive assembly, the magnetic drive assembly comprising: a first drive magnet having magnetic shielding on a portion thereof altering the magnetic field of the first drive magnet; a first motion magnet; and a first acceleration field created by the interaction between the first drive magnet and the first motion magnet as the first motion magnet is passed through the altered magnetic field of the first drive magnet.
 5. The turbine of claim 1, wherein the variable pitch blade is also configured such that as the blade rotates about the central axis, the blade may be pivoted relative the frame link from the second position to the first position.
 6. The turbine of claim 5, wherein the blade is pivoted toward and into the first position as the blade moves generally with oncoming wind.
 7. The turbine of claim 6, wherein the blade is pivoted toward and into the second position as the blade moves generally into oncoming wind.
 8. The turbine of claim 5, wherein the pivot range between the first position and the second position is from about 45 degrees to about 135 degrees.
 9. The turbine of claim 5, further comprising a position limiter to keep the blade from pivoting past the first position.
 10. The turbine of claim 9, further comprising a position limiter to keep the blade from pivoting past the second position.
 11. The turbine of claim 1, wherein at least one of wind or inertial forces cause the blade to pivot from the first position to the second position.
 12. A method for reducing the negative torque on a wind turbine, comprising: providing a turbine having variable pitch blade for rotation about a central axis, the variable pitch blade operably coupled with the central axis via a frame link; and positioning the variable pitch blade, frame link, and central axis, such that the variable pitch blade is pivoted relative the frame link from a first position to a second position so as to reduce negative torque on the central axis caused by the blade heading generally into oncoming wind.
 13. The method of claim 12, further comprising operably coupling the central axis to a generator for producing electricity.
 14. The method of claim 12, positioning the variable pitch blade, frame link, and central axis, such that the variable pitch blade is pivoted relative the frame link from the second position to the first position as the blade moves generally with oncoming wind.
 15. The method of claim 12, wherein the pivot range between the first position and the second position is from about 45 degrees to about 135 degrees.
 16. A wind turbine, comprising a variable pitch blade, which in addition to rotating about a central axis of the wind turbine, is configured to transition from a first position to a second position about a pivot point of the blade.
 17. The wind turbine of claim 16, further comprising a plurality of variable pitch blades, which in addition to rotating about a central axis of the wind turbine, are each configured to transition from a first position to a second position about a pivot point of the blade.
 18. The wind turbine of claim 16, wherein the blade is also configured to transition from the second position to the first position about the pivot point of the blade.
 19. The wind turbine of claim 18, wherein the blade is pivoted toward and into the first position as the blade moves generally with oncoming wind.
 20. The wind turbine of claim 19, wherein the blade is pivoted toward and into the second position as the blade moves generally into oncoming wind. 